Avril Lavigne is bringing out her bad side on her upcoming fifth studio album.

When the Canadian pop-rock singer had to channel her inner vixen for "Bad Girl," off her untitled September album, there was only one person she had in mind to help: Marilyn Manson.

"It was last minute," Lavigne said of recruiting Manson for the track. "I was sitting there at the board thinking Manson would be perfect on this track, so I texted him, and he's like, 'I'll come over and I'll hear it.' So he came at 4 o'clock in the morning. ... Yes, it was one of those nights."

The Manson/Lavigne duo may seem like an unlikely one, but they are actually longtime friends. (Lavigne first met the rocker at one of his concerts when she was 18.) In fact, he is the one responsible for Lavigne's half-shaved haircut that she sported last year.

"I had wanted to shave the side of my head for quite some time, and I used to put it in a braid there [side of her head] and so it was kind of like shaving it," Lavigne said "And then one night, it was on my adventure to France. During my adventure when I was living there, we were hanging out backstage and we were with his band having a few drinks and I was like, 'Let's shave my head. I'm ready; let's do this!' He's like that, though. He has fun. He wears his makeup; his wardrobe is very visual. I like his style."

Manson is one of two confirmed collaborations on the album, with the other being Lavigne's fiancé, Nickleback singer Chag Kroeger.